I spent plenty of time as a kid in music class learning how long notes last. A quarter-note lasts 1 beat, a half-note lasts 2 beats, etc.
But that knowledge, on its own, obscures and possibly undermines more sophisticated approaches to music-making. The important questions are “What beat does this start on?” and “What beat does it cut off on?”, not “How long does this note last?”
A singer who knows just how long a note lasts can easily find themself off by a beat, due to a moment of inaccurate counting. But a singers who knows the start and end of each note or phrase will never be off, so long as they maintain a sense of the underlying rhythm.
I’m as guilty as my teachers of asking, “How long does this note last?” but I think I’ll be a better teacher if I banish it. While understanding relative duration is important, moving past note durations into an understanding of the framework will make for better music-making and faster integration of the music.